Senate Democrats have been desperately trying to move the national conversation away from Obamacare to just about anything else before the midterm elections — “paycheck fairness,” the minimum wage, even the Koch brothers.

But President Obama’s choice of Sylvia Burwell to replace Kathleen Sebelius as secretary of Health and Human Services thrusts Obamacare right back into the national spotlight — and with it Obama’s false promise that “if you like your health-care plan, you can keep your health-care plan.”

Marc A. Thiessen

A fellow with the American Enterprise Institute, Thiessen writes a weekly column for The Post.

The agency Burwell heads, the Office of Management and Budget, is responsible for the president’s budget. But OMB also has another, lesser-known responsibility: fact-checking presidential speeches. Every proposed presidential utterance is scrubbed for accuracy by OMB.

When speechwriters finish a draft presidential address, it is circulated to the White House senior staff and top cabinet officials in what is known as the “staffing process.” As part of that process, nonpartisan career policy experts at OMB review the speech and are responsible for attesting to the factual accuracy of everything the president says.

So thanks to Burwell’s nomination, Americans may finally get to the bottom of how the biggest presidential lie in recent memory made it though OMB’s fact-checking process — not once but dozens of times.

The first time the lie surfaced — when Obama told the American Medical Association on June 15, 2009, “If you like your doctor, you will be able to keep your doctor, period. If you like your health-care plan, you’ll be able to keep your health-care plan, period. No one will take it away, no matter what” — it wasn’t on Burwell’s watch.

But Burwell was OMB director when Obama declared on Sept. 26, 2013: “Now, let’s start with the fact that even before the Affordable Care Act fully takes effect, about 85 percent of Americans already have health insurance — either through their job, or through Medicare, or through the individual market. So if you’re one of these folks, it’s reasonable that you might worry whether health-care reform is going to create changes that are a problem for you — especially when you’re bombarded with all sorts of fear-mongering. So the first thing you need to know is this: If you already have health care, you don’t have to do anything.”

Burwell should explain to Congress and the American people how her office allowed blatant falsehoods to get into presidential speeches, including whether political aides overruled career policy advisers who warned that the president’s claims were untrue.

This isn’t just a rehashing of ancient history, because the worst impacts of Obama’s lie are still to come. While some 6 million Americans lost their individual market plans last fall, tens of millions of Americans will see their employer-based health plans canceled or changed dramatically when the employer mandate kicks in. Obama has delayed the mandate for a year in an effort to prevent cancellations before the midterm elections. But on Burwell’s watch, he has also falsely promised that those with employer-based plans have nothing to worry about.

In October 2013, Obama declared: “Keep in mind that the individual market accounts for 5 percent of the population. So when I said you can keep your health care, I’m looking at folks who’ve got employer-based health care.” But “folks who’ve got employer-based health care” are going to lose their coverage, too — in fact, some businesses like Target, Trader Joe’s and Home Depot are already canceling plans and scaling back health benefits before the mandate kicks in. Burwell should be forced to explain how that Obama lie made it thought the OMB fact-checking process.

If Senate Democrats are smart, they will be the ones pushing hardest for this information — especially the 12 up for reelection this year who repeated the Obama lie. Sen. Mary Landrieu (La.) pledged, “If you like the insurance that you have, you’ll be able to keep it.” Sen. Mark Pryor (Ark.) said Arkansans want to know “are we gonna be able to stick with our plan? The answer is yes.” Sen. Kay Hagan (N.C.) promised, “If you like your insurance and your doctors, you keep them.” Sen. Jeanne Shaheen (N.H.) swore, “Everyone will have the freedom to keep their health plan if they like it.” Sen. Mark Begich (Alaska) vowed, “Alaskans who have health insurance now, and are happy with it, can keep it.” Sen. Mark Warner (Va.) declared, “I’m not going to support a health-care reform plan that’s going to take away the health care you’ve got right now or a health-care plan that you like.” The rest made similar pledges.

Burwell should not be confirmed until she explains how OMB allowed the president of the United States to lie — repeatedly — to the American people. If Democrats don’t demand answers, they can be sure that Republicans will. Since avoiding the subject is not an option, her hearings will be a fascinating insight into the Democrats’ 2014 strategy on Obamacare. Vulnerable Senate Democrats have two choices: Come to Obama’s defense, or use the Burwell hearings to separate themselves from the president and blame him for misleading them like he misled the rest of America.